Sunscreening method and composition containing film forming polyamide material

ABSTRACT

Sunscreening compositions and methods of using the same to protect human skin from erythema-causing radiation by applying to the skin compositions containing a cosmetic carrier, at least one ultraviolet absorbing material which has a maximum absorption peak between 280 millimicrons to about 320 millimicrons and a polyamide resinous material which is capable of forming a film and is alcohol-soluble. Sunscreening compositions containing the polyamide resinous materials, when applied to the skin, form a long lasting protective film which resists removal by water and perspiration.

United States Patent [191 Karg [ SUNSCREENING METHOD AND COMPOSITIONCONTAINING FILM FORMING POLYAMIDE MATERIAL [75] Inventor: Gerhart Karg,Pompton Lakes, NJ.

[73] Assignee: Avon Products, Inc., New York,

[22] Filed: June 13, 1972 21 Appl. No.: 262,375

[52] U.S. Cl. 424/59; 424/47; 424/60; 424/78; 424/81; 424/170 [51] Int.Cl A61] 23/00 [58] Field of Search 424/59, 60, 78 A; 260/78 A [56]References Cited UNITED STATES PATENTS 3,529,055 9/1970 Skoultchi et a1424/59 X 3,622,545 11/1971 FOldi et al 260/78 A I 3,666,732 5/1972Skoultchi et al 260/78 A FOREIGN PATENTS OR APPLICATIONS 862,718 2/1971Canada 424/59 [451 July 15,1975

9/1948 France 424/60 OTI-IER PUBLICATIONS Steinhauer et al., Chem. Abs.1970, Vol. 73, pp. 1l2871x.

[57] ABSTRACT Sunscreening compositions and methods of using the same toprotect human skin from erythema-causing radiation by applying to theskin compositions containing a cosmetic carrier, at least oneultraviolet absorbing material which has a maximum absorption peakbetween 280 millimicrons to about 320 millimi crons and a polyamideresinous material which is capable of forming a film and isalcohol-soluble. Sunscreening compositions containing the polyamideresinous materials, when applied to the skin, form a long lastingprotective film which resists removal by water and perspiration.

8 Claims, No Drawings SUNSCREENING METHOD AND COMPOSITION CONTAININGFILM FORMING POLYAMIDE MATERIAL BACKGROUND OF THE INVENTION It isbelieved desirable in our society to secure tanning of the skin forpurposes of appearance. It is well known that ultraviolet radiationproduced by the sun or by sun lamps and other tanning means between thewave lengths of about 280 millimicrons to about 320 millimicrons areresponsible for distressing burning which is suffered by overexposure tosuch tanning means while the ultraviolet radiation of longer wavelengthsof up to about 420 millimicrons causes the aesthetically desirabletanning coloration of the skin. In order to prevent or substantiallyreduce sunburn while promoting the development of a tanning appearancevarious so called sunscreening formulations have been produced and arecommercially available. These are adapted to be applied over the bodyareas which are to be exposed and their formulations generally contain acompound which can absorb ultraviolet radiation in the range of fromabout 280 to 320 millimicrons and thus alleviate the problems oferythema.

In addition to the above noted primary sunscreening function, acommercially suitable agent should be essentially resistant to removalby fresh or salt water or through the perspiration of the user while, atthe same time, be completely removable from the skin upon washing withordinary soap and water. It should be, moreover, fully compatible withorganic solvents as well as with the various ingredients which may bepresent in suntan preparations such as, for example, oils, perfumes,pigments, and aerosol propellants. Finally, the sunscreen agent shouldbe fully resistant to any breakdown resulting from the exposure to theultraviolet radiation and, most certainly, it should be entirelyharmless to the user.

In the past various chemical compounds have been utilized assunscreening agents for suntan formulations. Compounds, such asaminobenzoic acid, its derivatives and esters as well as substitutedbenzophenones and other well known compounds which absorb in the rangeof from 280 millimicrons to 320 millimicrons have been commonly used incommercially available suntan preparations. These preparations, however,are not substantive to the skin and, therefore, do not yield a longlasting protective screen.

Suntanning preparations are generally used in hot weather and at beacheswhere people enjoy bathing. Therefore, compositions containingcrystallizable ultraviolet absorbers which are generally used lack theability to be long lasting. When the volatile vehicle, in which thesecompounds are formulated, evaporates from the skin the sunscreeningcompound rapidly crystallizes or forms globular material on the skinwhich is easily removable by the action of water or perspiration.Furthermore, the continuity of the protective material is thus brokenand the desired protection is destroyed. To overcome these variousdeficiencies attempts have been made to incorporate ultravioletabsorbing groups in compounds which would be more resistant to theaction of water or would be insoluble in water. Higher esters ofaminobenzoates are known to form an oily film which are more resistantto removal by water. These materials, although overcoming one problem,are limited in scope due to their melting and boiling points,

their reactivity with other materials as well as their tendency to breakdown under ultraviolet radiation.

SUMMARY OF THE INVENTION It has now been found that sunscreeningcompositions which are useful in absorbing the erythemaproducingradiation can be made comprising an ultraviolet absorbing material and apolyamide resinous material having the properties of being soluble inalcohol and capable of forming a film material. The polyamide materialcan be encompassed into the various cosmetic carrier materials known tobe useful by the practitioner. The resultant formulations, whentopically applied to the skin, will form a film material which willresist removal by the action of fresh or salt water or throughperspiration of the user.

DETAILED DESCRIPTION OF THE INVENTION Sunscreening formulationscontaining polyamide resinous material are capable of screening harmfulultraviolet radiation while permitting transmission of the beneficialrays. In this manner the individual may subject himself to sunlight orsun lamps to cause the aesthetically desirable tanning of the skin whilesubstantially alleviating the problems of sunburn and its accompanyingdiscomfort and pain.

The compositions of the present invention are applied to the skin in anyfugitive dermatologically acceptable carrier. The carrier material shallcontain at least one compound which has a characteristic maximumultraviolet absorption peak between about 280 millimicrons and about 320millimicrons. In addition, the carrier material shall also contain apolyamide film forming material as herein described. The compositionsmay be in the form of a homogenous solution or dispersion. The fugitivecarrier material contained therein may be alcohols, water-alcoholmixtures and the like. The carrier may also be chosen from oil-inwateremulsions wherein the amount of oil present is not sufficient to permitformation of an over-plasticized polymeric film. The specific type ofcarrier material or carrier system which is to be utilized will dependupon the type of application, the degree of application and thedesirability of particular bases to different users.

The polyamide materials which have been found most useful in forminglong lasting sunscreen compositions are those which are insoluble inwater, are compatible with the carrier material and which, uponevaporation of said carrier material, form a substantive film material.

Polymeric material useful herein includes homopolymers and copolymers ofacrylamide. The pendant amide moiety may have substituted groupsattached to the nitrogen atoms wherein said substituted groups may beselected from the groups consisting of hydrogen, alkyl, substitutedalkyl, alkenyl, aryl, substituted aryl and alkaryl groups. The groups oneach nitrogen atom present in the polyacrylamide may have the same ordissimilar substitution. As to the alkyl groups they are preferably C,to C such as methyl, ethyl, n-propyl, butyl, amyl, hexyl, heptyl, nonylgroups and the like; the alkenyl groups can be allyl, methallyl, crotyland the like; and the substituted alkyls are exemplified by the cyano,hydroxy, alkoxy or halo C -C radicals with examples being cyanoethyl,cyano-n-propyl, cyano-n-butyl, hydroxyethyl, hydroxyisopropyl,hydroxyhexyl, methoxymethyl, methoxypropyl, propoxypropyl, butyoxyethyl,chloropropyl, chloroethyl, chlorodecyl and the like. With respect to thearyl radicals these can be phenyl, tolyl, xylyl, diphenyl and the like;the substituted aryl radicals are illustrated by anisyl, hydroxyethylphenyl, meta-chlorotolyl and the like; and the alkyaryl groups can bebenzyl, phenethyl, phenol n-propyl, 2,4- dimethylbenzyl and the like.The polymeric material contemplated herein does not of necessity have tohave all substituted groups the same. Therefore, the polymercontemplated may contain nitrogen atoms of the pendant amide groupswhich are unsubstituted, monosubstituted or disubstituted and are allthe same or, alternatively, pendant groups which differ one from'anothersuch as where some pendant groups are unsubstituted amide groups andsome are substituted amides. The resulting polymeric material must beinsoluble in water, be capable of forming a substantive film and besoluble in alcohols.

Polymeric materials useful herein include homopolymers and copolymers ofacrylamide such as polyacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N,N-dibutylacrylamide, N,N-di(,8-hydroxyethyl)acrylamide, N,N-dimethoxymethylacrylamide,N-methylacrylamide, N-ethyl acrylamide, N-methoxymethyl acrylamide,N-ethyl-N-cyanoethyl acrylamide, N-phenyl acrylamide, (N,N-dimethyl)(NN'-diethyl)acrylamide, (N,N-dimethyl) (N-ethyl) acrylamide,(N,N-diphenyl) (N'-methyl)acrylamide and the like.

Polyacrylamides useful in this invention may be made in any of the knownmethods such as by free radicalpolymerization of the desired monomericconstituents.

Polyamides useful in forming the long lasting sunscreen composition ofthis invention may be polymers formed from the reaction of polyamineswith a polybasic acid. Methods of preparing these polyamides bycondensation of polyamines and polycarboxylic acids or anhydrides arewell known in the art and need not be described here. The polyamides maybe derived from such polyamines as ethylenediamine, diethylenetriamine,triethylenetetramine, tetraethylenepentamine, propylenediamine,1,4-diaminobutane, 1,3- diaminobutane, hexamethylenediamine, 3 ,3

iminobispropylamine and the like. Typical polycarboxylic acids which maybe condensed with the polyamines to form the desired polyamide areoxalic, malonic, succinic, glutaric, adipic, palmitic, suberic, azelaic,sebacic, malic, phthalic, cyclohexandicarboxylic, and the like as wellas their isomers, homologs and andydrides. Alternately, or in additionto the above polycarboxylic acids, the polyamide may be formed fromunsaturated polycarboxylic acids or anhydrides such as maleic, fumaric,citraconic and itaconic acids and the like. It is understood that thepolyamide formed shall be water insoluble, compatible with the carriermaterial used and having the property of forming a film material uponevaporation of the carrier material.

The amount of polymeric material which is incorporated into thesunscreening compositions may range from about 0.1 to about 50 weightpercent based on the total weight of the composition with a preferredrange of from about 5 to about 25 percent. While in some instancesgreater or lesser amounts of the polymeric material may be used, it hasbeen found, in general, that the foregoing range of polymeric materialincorporated into the sunscreening compositions is most suitable inyielding a film-forming composition which is resistant to removalby'fresh or salt water or through perspiration.

The long-lasting sunscreening compositions, as herein described, containone or more additional ultraviolet absorbing materials which have amaximum absorption peak in the range of from 280 millimicrons to 320millimicrons. Examples of such compounds are the aminobenzoic acids oresters of these materials, substituted benzophenones, compounds having abenzanilide nucleus, organosilicon esters and other compounds which arewellknown to those skilled in the art. These selective ultravioletabsorbing compounds may be used in the composition of this invention inquantities ranging from 0.1% to about 10% based on the total weight ofthe sunscreening composition. Normally effective amounts of thesematerials range from 0.1% to about 6% depending upon the activity of thechromophoric absorbing group.

The cosmetic carrier material may be a C C lower alcohol or mixtures oftwo or more different alcohols. The alcohols may be any dermatologicallyacceptable material which will evaporate from the skin after applicationsuch as methanol, ethanol, propanol, isopropanol and the like. Suchalcohols may be used alone or with other polyols such as ethyleneglycol, 1,2- propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol,glycerol, trimethylol ethane pentaerythritol, sorbitol and the like.

The cosmetic carrier material may be a mixture of the above alcoholswith water. Normally the amount of water present is less than themajority of the total carrier material. The maximum amount of waterwhich may be present in dependent upon the compatibility of the specificpolyamide used with the alcohol-water mixture. In addition, an oil maybe present. The oil material, such as a mineral, vegetable or animaloil, to be limited to such quantity so as to not plasticize thepolyamide resultant film to the degree that a tacky material results.

The sunscreening compositions, as described hereinabove, are applied tothe skin in any convenient manner such as by hand rubbing small amountsonto the exposed skin which is to be subjected to the suntan causingradiation. Alternately, the composition may be sprayed by an aerosolcontainer onto the exposed skin. The applied composition will form afilm on the treated skin which is resistant to removal by the abrasiveaction of fresh or salt water or through perspiration of the user.Instead it remains as a continuous sheet material which is substantiveto the skin surface. This sheet material contains entrapped therein theultraviolet absorbing compound or compounds which effectively protectthe skin from erythema-causing rays.

In addition, other of the usual components such as perfumes, fillers,dyes, colorants, emulsifiers and the like may be added to the longlasting sunscreen compositions described hereinabove. The type andamount of such additional components will depend on the factors EXAMPLE1 Compositions are prepared by forming aqueousalcoholic solutions havingthe following composition:

Ethyl alcohol 78 parts Propylene glycol l parts Water 5 parts PolyN.N-dimethyl acrylamide 7 parts Colorant and Perfume to suit Thesolutions are each mixed with 4% of one of the following UV absorbingcompounds:

(a) Ethyl-1,2-diphenylethylene-l-carboxylic acid (b) Diethylp-dimethylamino-benzalmalonate (c) Di-isobutyl p-dimethoxymethylaminobenzalmalonate (d) Ethyl p-dimethyl aminocinnamate (e) lsobutylp-dihydroxymethylamino cinnamate (f) Amyl p-dimethylamino benzoate (g)Ethyl p-dimethylamino benzoate (h) N,N-dimethyl benzocaine (i)p-dimethylamino benzamide Samples are applied to the skin and thetreated areas exposed to ultraviolet rays (Xenon-arc Solar Simulator)for time periods equivalent to from 2 to 6 times the previouslyestablished minimum erythema] dose for each volunteer. Substantially noerythema was observed at the treated sites over a twenty-four hourperiod.

To determine the substantivity of the compositionsthe volunteers hadareas of their forearms treated with each of the test samples, exposingthe treated area to the UV source for a time greater than theestablished minimum erythemal dose (MED) and then subjecting the areasto water (8090F.) immersion throughs for periods ranging from 5 to 15minutes and re-exposing the treated areas. Observation of the treatedareas after 24 hours showed substantially no reddening.

EXAMPLE II Alcoholic substantive sunscreen compositions are prepared bymixing 70 parts ethanol, 10 parts glycerol, parts of a polyamide resinmade from ethylene diamine and an unsaturated dimer acid (18carbons/carboxyl group) and 5 parts of each of the UV absorvingcompounds listed in Example I.

The compositions are tested in the same manner as the compositions ofExample I. The compositions showed protection to erythema causing raysand substantive properties after exposure to water.

EXAMPLE II] An alcoholic substantive sunscreen composition is preparedby mixing the following:

Ethanol 70 parts Polyamide resin (as described in Example ll) 15 parts-Continued Oleyl alcohol-propylene oxide adduct 12 pansAmyl-para-dimethyl aminobenzoate 3 parts The composition is tested inthe same manner as the compositions of Example I. The composition showedprotection .to erythema causing rays and substantive properties afterexposure to water. The MED increase for the tested volunteers was 3.6before exposure to water and remained at 3.6 after exposure to water.

EXAMPLE IV A composition is prepared by mixing the following:

Ethanol parts Polyamide resin (1,3 propylene diamineunsaturated dimeracid) 15 parts Oleyl alcohol/propylene oxide adduct 9 parts Dimethylprocaine decyl bromide 6 parts The composition was tested in the mannerdescribed in Example I. The treated areas of the skin showed goodprotection qualities and when tested for substantive properties showed aMED increase of 2.7 prior to water treatment and 2.7 after suchtreatment. The treated area, therefore, has equal protection before andafter subjection to water.

EXAMPLE V A comparison test was made in which an erythema UV absorbingcompound is mixed with a carrier material which does not contain apolyamide resin. The composition comprises:

Ethanol 82 parts Polyoxyethylene 10 parts Dimethyl procaine octadecylbromide 8 parts The sample is tested as described in Example I. Thesample showed a high degree of protection but the substantive test gavea MED value of 6 prior to water treatment and 0.0 after such treatment.

It will be understood that it is intended to cover all changes andmodifications of the examples of the invention herein chosen for thepurpose of illustration which do not constitute departures from thespirit and scope of the invention.

What is claimed is:

1. A method of protecting human skin from erythema-causing radiationcomprising applying to the skin a sunscreening composition containingfrom about 0.1 to about 10 percent of the composition of at least oneultraviolet absorbing material having a maximum absorption peak betweenabout 280 millimicrons and 320 millimicrons and from about 0.1 to about50 percent of the composition of a water-insoluble, alcoholsoluble,film-forming polyamide material, said materials being incorporated infrom about 40 percent to 99.8 percent of the composition of a cosmeticcarrier material selected from the group consisting of C -C alcohol, C-C alcohol mixtures and C -C alcohol-water mixtures, said maximum amountof water present in the alcohol-water mixture being dependent upon thecompatibility of the polyamide used; and allowing said composition toform a film on the skin.

2. The method of protecting human skin from erythema-causing radiationaccording to claim 1 wherein 7 v the polyamide material is a waterinsoluble, alcohol soluble, film forming polyacrylamide.

3. The method of protecting human skin from erythema-causing radiationaccording to claim 1 wherein the polyamide material is awater-insoluble, alcohol soluble, film forming condensation product ofat least one polycarboxylic acid and at least onepolyamine.

4. The method of protecting human skin from erythema-causing radiationaccording to claim 1 wherein the cosmetic carrier is a fugitive C -Calcohol-aqueous mixture having the alcoholic content of said mixture inamounts of at least 50 percent.

5. A substantive composition for protecting skin from erythema-causingradiation comprising from about 0.1 to about percent by weight of anultraviolet absorbing material having a maximum absorption peak betweenabout 280 millimicrons and 320 millimicrons and from 0.1 to 50 percentbased on the total weight of the composition of a polyamide resinousmaterial which is water-insoluble, alcohol soluble and capable offorming a substantive film material, said'materials being incorporatedin from about 40 to 99.8 percent by weight of a cosmetic carrierselected from the group consisting of C -C alcohol, C -C alcoholmixtures and C -C alcohol-water mixtures, said maximum amount of waterpresent in the alcohol-water mixtures being dependent upon thecompatibility of the polyamide used.

6. The substantive composition according to claim 5 wherein thepolyamide resinous material is a condensation product of at least onepolycarboxylic acid and at least one polyamine.

7. The substantive composition according to claim 5 wherein thepolyamide resinous material is a polyacrylamide.

8. A substantive composition according to claim 5 wherein the cosmeticcarrier is a C -C alcohol-water mixture having an alcohol content ofsaid mixture in amounts of at least 50 percent.

1. A method of protecting human skin from erythema-causing radiationcomprising applying to the skin a sunscreening composition containingfrom about 0.1 to about 10 percent of the composition of at least oneultraviolet absorbing material having a maximum absorption peak betweenabout 280 millimicrons and 320 millimicrons and from about 0.1 to about50 percent of the composition of a water-insoluble, alcohol-soluble,film-forming polyamide material, said materials being incorporated infrom about 40 percent to 99.8 percent of the composition of a cosmeticcarrier material selected from the group consisting of C1-C5 alcohol,C1-C5 alcohol mixtures and C1-C5 alcohol-water mixtures, said maximumamount of water present in the alcohol-water mixture being dependentupon the compatibility of the polyamide used; and allowing saidcomposition to form a film on the skin.
 2. The method of protectinghuman skin from erythema-causing radiation according to claim 1 whereinthe polyamide material is a water insoluble, alcohol soluble, filmforming polyacrylamide.
 3. The method of protecting human skin fromerythema-causing radiation according to claim 1 wherein the polyamidematerial is a water-insoluble, alcohol soluble, film formingcondensation product of at least one polycarboxylic acid and at leastone polyamine.
 4. The method of protecting human skin fromerythema-causing radiation according to claim 1 wherein the cosmeticcarrier is a fugitive C1-C5 alcohol-aqueous mixture having the alcoholiccontent of said mixture in amounts of at least 50 percent.
 5. ASUBSTANTIVE COMPOSITION FOR PROTECTING SKIN FROM ERYTHEMA-CAUSINGRADIATION COMPRISING FROM ABOUT 0.1 TO ABOUT 10 PERCENT BY WEIGHT OF ANULTRAVIOLET ABSORBING MATERIAL HAVING A MAXIUM ABSORPTION PEAK BETWEENABOUT 280 MILIMICRONS AND 320 MILIMICRONS AND FROM 0.1 TO 50 PERCENTBASED ON THE TOTAL WEIGHT OF THE COMPOSITION OF A POLYAMIDE RESINOUSMATERIAL WHICH IS WATER-INSOLUBLE, ALCOHOL SOLUBLE AND CAPABLE OFFORMING A SUBSTANTIVE FILM MATERIAL, SAID MATERIALS BEING INCORPORATEDIN FROM ABOUT 40 TO 99.8 PERCENT BY WEIGHT OF A COSMETIC CARRIERSELECTED FROM THE GROUP CONSISTING OF C1-C5 ALCOHOL, C1-C5 ALCOHOLMIXTURES AND C1-C5 ALCOHOLWATER MIXTURES, SAID MAXIMUM AMOUNT OF WATERPRESENT IN THE ALCOHOL-WATER MIXTURES BEING DEPENDENT UPON THECOMPATIBILITY OF THE POLYAMIDE USED.
 6. The substantive compositionaccording to claim 5 wherein the polyamide resinous material is acondensation product of at least one polycarboxylic acid and at leastone polyamine.
 7. The substantive composition according to claim 5wherein the polyamide resinous material is a polyacrylamide.
 8. Asubstantive composition according to claim 5 wherein the cosmeticcarrier is a C1-C5 alcohol-water mixture having an alcohol content ofsaid mixture in amounts of at least 50 percent.